The positive impact of having a dog is the focus of a new study.

Owning a pooch can reduce the risk death by a third, according to a new Swedish study. It adds to mounting evidence about the benefits of living with a canine companion.

Swedish scientists used national data on health, hospital visits and dog ownership from 2001, the year when registering dogs became mandatory. Researchers began by looking at 3.4 million Swedes aged 40 to 80, who in 2001, had no history of heart disease.

Over the next 12 years, investigators found that dog owners in general had a lower risk of death due to cardiac disease, according to the research published in the Scientific Reports.

The decrease was strongest in people who lived alone. Solo residents had a 33% reduction in mortality and an 11% cut in the risk of heart attack compared to people who lived alone without a dog.

“A very interesting finding in our study was that dog ownership was especially prominent as a protective factor in persons living alone,” said Mwenya Mubanga, lead junior author of the study.

“Another interesting finding was that owners to dogs from breed groups originally bred for hunting were most protected,” Mubanga added.

That includes dogs like golden retrievers, Labrador retrievers and pointers.

While the study didn’t look at why dogs are good for people’s health and longevity, researchers suggested reasons ranging from increased physical activity, social contact and reduced stress and even boost microbiome diversitythat is essential for good health.